Friction door holder

ABSTRACT

A friction door holder having a door frame mounting bracket and a door supported channel formed with an elongated guide slot. The channel houses a self-lubricating friction assembly. A drive arm pivoted to the mounting bracket moves the friction assembly within the channel. The friction assembly comprises a slide block which has a generally U-shaped elongated body formed with generally parallel elongated depending sides positioned closely adjacent the sides of the channel and joined together by a base section located adjacent the guide slot. The slide block body includes firstly an elongated guide head projecting from the base and sandwiched between the edges of the guide slot, and secondly a plurality of projecting retainer legs depending from the corner extremities of the depending sides towards the channel bottom. A metal plate carrying a friction liner is housed within the slide block and is retained between the slide block legs; and an elongated cam spring is housed within the slide block with one end fixed to the slide block and the other end being free to move relative the slide block. An adjustment screw carried by the slide block contacts adjustably the free end of the cam spring to vary the degree of friction engagement between the friction liner and the channel. The slide block is preferably fabricated of a solid plastic, such as nylon, containing a homogeneously dispersed solid lubricant, such as molybdenum disulfide.

United States Patent Morrison et al. I

[ FRICTION DOOR HOLDER [72] Inventors: Richard J. Morrison, Wilmette;

Arthur A. Schlumpf, Chicago; Albert J. Martino, West Dundee, all of Ill.

[73] Assignee: Rixson lnc., Franklin Park, Ill.

[22] Filed: June 22, 1970 [21] Appl. No.: 48,090

[52] US. Cl. ..l6/49, 292/275, 16/82 [51] Int. Cl. ..E05f 5/00 [58]Field of Search ..292/272, 275; 76/49, 82

[56] References Cited UNITED STATES PATENTS 1,573,456 2/1926 Sibley..292/275 1,344,507 6/1920 Hagstrom ..292/275 1,353,523 9/1920 Eustege..292/275 1,569,634 l/l926 Sibley ..292/275 X 2,277,316 3/1942 Garrison16/49 X 2,289,092 7/1942 Bernard 16/49 Primary Examiner-Bobby R. GayAssistant Examiner--Peter A. Aschenbrenner Attorney-Augustus G. Douvas 57 ABSTRACT A friction door holder having a door frame mounting [451 Aug.15,1972

bracket and a door supported channel formed with an elongated guideslot. The channel houses ,a selflubricating friction assembly. A drivearm pivoted to the mounting bracket moves the friction assemblywithin'the channel.

The friction assembly comprises a slide block which has a generallyU-shaped elongated body formed with generally parallel elongateddepending sides positioned closely adjacent the sides of the channel andjoined together by a base section located adjacent the guide slot. Theslide block body includes firstly an elongated guide head projectingfrom the base and sandwiched between the edges of the guide slot, andsecondly a plurality of projecting retainer legs depending from thecorner extremities of the depending sides towards the channel bottom. Ametal plate carrying a friction liner is housed within the slide blockand is retained between the slide block legs; and an elongated camspring is housed within the slide block with one end fixed to the slideblock and the other end being free to move relative the slide block. Anadjustment screw carried by the slide block contacts adjustably the freeend of the cam spring to vary the degree of friction engagement betweenthe friction liner and the channel.

The slide block is preferably fabricated of a solid plastic, such asnylon, containing a homogeneously dispersed solid lubricant, such asmolybdenum disultide.

7 Claims, 10 Drawing Figures PKTE'N'TEflAus 15 I972 SHEET 2 BF 2 IV V EIV 70/? 5' Ric/70rd J. Morrison Arthur A. 56/7 lumpf Albert J. Mart/n0Attorney FRICTION DOOR HOLDER BACKGROUND OF THE INVENTION Friction doorholders are well known in the art.

These devices serve to hold a door at a desired open position with aminimum of manual effort to attain the hold position. Additionally, theholding function must be manually overcome readily in order to close thedoor.

The repetitive opening and closing of a door employing a friction holdersubjects the holder components to considerable wearing forces and inextreme cases to destructive shock.

Excessive component wear ultimately introduces looseness or play in theholding function which is detrimental to good operation. Additionally,this condition contributes to the premature deterioration of the holderand to user dissatisfaction.

Accordingly, there is a substantial demand for door holders capable ofwithstanding reliably the door cycling generated by heavy traffic whichrequires repetitive opening and closing and also intermediate holdingfunctions.

DETAILED DESCRIPTION OF THE PRIOR ART SUMMARY OF THE INVENTION Thepresent invention is primarily directed to improvements in the frictionassembly which charac terizes friction door holders. This assembly mustserve two functions which at the outset appear conflicting. Frictionmust be attained to provide the holding function, but at the same timethe door must be readily movable to a desired position without excessivemanual exertion. Additionally, the friction and also the movingfunctions must not produce an excessive wear of components.

The improved friction assembly of this invention is characterized by aplastic slide block that glides quietly and smoothly, withstandstremendous shock, and has inherent lubricity which makes lubricationunnecessary. This block features wall and guide surfaces that fitclosely within a channel. The close fit attained between the slide blockand the channel prevents excessive play which would otherwise lead toloose holding of the door. However, because of the self-lubricatingfunction of the slide block, undesired wear and friction are notcreated. Thus, life expectancy of the holder is greatly extended.

Additionally, the slide block is simply constructed so that it mayretain and slide reliably the actual friction element which may beindividually adjusted for proper operation without the customaryallowance for periodic service wear in the slide block.

DETAILED DESCRIPTION OF THE DRAWINGS In order that all of the structuralfeatures for attaining the objects of this invention may be readilyunderstood, reference is herein made to the accompanying drawings,wherein:

FIG. 1 is a simplified perspective view showing the door holder of thisinvention surface mounted on a flush door;

FIG. 2 is a section view taken along line 22 of FIG. 1 showing thesurface mounted channel and its friction assembly, the drive arm, andthe frame bracket;

FIG. 3 is a simplified perspective view showing the door holder modifiedfor concealed mounting on a flush door;

FIG. 4 is a section view taken along line 44 of FIG. 3 showing theconcealed mounted channel and its friction assembly, the drive arm, andthe frame bracket;

FIG. 5 is a perspective view of the concealed door holder of FIG. 3 withportions of the channel broken away to show the general details of thefriction assembly and the stop shock assembly;

FIG. 6 is a section view taken along the line 6-6 of FIG. 5 showingdetails of the friction assembly when in friction holding contact withthe channels;

FIG. :7 is an exploded view of the friction assembly;

FIG. 8 is a section view taken along the line 88 of FIG. 5 showingdetails of the friction assembly when in friction holding contact withthe channel;

FIG. 9 is a view of the stop shock assembly with the end block shown insection; and

FIG. 10 is a perspective view showing conventional modifications in thechannel for surface mounting.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 and 2, door holder11 of this invention is shown surface mounted to flush door 12. Theprincipal parts of door holder 11 comprise frame bracket 13, frictionassembly drive arm 14, channel 15, friction assembly 16 (FIG. 2), andshock assembly 17 (FIG. 9). Frame bracket 13 is applied to door stop 18in the particular embodiment shown in FIGS. 1 and 2.

It is the purpose and function of the door holder to enable door 12 tobe held open at any position, from slightly open to approximately 1 10.This function is attained generally by friction assembly 16 (see FIG. 8)applying a holding friction force to channel 15 (or channel 23 in FIG.3), as is hereafter explained in detail. This friction force is, ofcourse, overcome by the manual application of a door opening or closingforce to door 12 so that the door may be placed at a desired positionrelative frame 19. Stop shock assembly 17 (FIG. 9) serves as a shockabsorber for minimizing a racking force in the event door 12 issubjected to an ex cessive door opening force.

FIGS. 3 and 4 show the basic door holder of FIGS. 1

and 2 modified in a conventional manner so that this door holder may beapplied in a concealed manner to the top edge of door 12. In thisembodiment, the concealed holder 20 comprises frame bracket 21, frictionassembly drive arm 22 and channel 23, all of which cor respond tocomponents 13, 14 and 15, previously described with reference to FIGS. 1and 2.

The major difference in the door holder embodiment of FIGS. 1 and 2 ascompared with that of FIGS. 3 and 4 is that horizontal mounting holes 24and 25 are provided for channel of FIG. 1 through which a plurality ofscrews 26 (FIG. 2) fix the channel to door 12. In the channel of FIG. 3,however, vertical mounting holes 27 and 28 are provided so that aplurality of screws 29 (FIG. 4) may fix the channel to door 12.

Channel 23 houses friction assembly 16 and stop shock assembly 17, whichare basically identical in construction with those of the door holderembodiment of FIGS. 1 and 2.

For illustrative purposes, FIGS. 5 through 8 show the details of theimproved friction assembly 16 which characterize this invention inassociation with the concealed door holder shown in FIGS. 3 and 4. Itshould be understood that with the exception of the mounting holes, thedoor holder embodiment of FIGS. 1 and 2 and that of FIGS. 3 and 4 areessentially the same.

Referring now to FIGS. 5 through 8, door holder 20 comprises a channel23 which may be preferably fabricated of stainless steel, steel orbronze. Galvanic corrosion is eliminated by the use of a plastic slideblock as hereafter described. Channel 23 may be generally square orrectangular in construction and this channel includes vertical sidewalls 30 and 31 joined together by bottom 32 and including also a top 33which is formed with an elongated guide slot 34. Friction assembly 16 ishoused within channel 23. Additionally, stop shock assembly 17 is alsohoused within channel 23.

The left end of channel 23, as viewed in FIG. 5, receives plastic block35 which is formed with hole 28 through which mounting screw 29 passesas is shown in FIG. 4.

The right end of channel 23, as viewed in FIG. 5, receives plastic block36 which is formed with hole 27 which likewise receives a screw, such as29, for mounting the channel.

Friction assembly 16 reciprocates within the track provided by thehollow channel 23. Its left most movement is limited by block 35, andits right most movement is limited by stop shock assembly 17 which willbe hereinafter explained with reference to FIG. 9.

Friction assembly 16 comprises a slide block 40 which has a generallyU-shaped elongated body formed with generally parallel elongateddepending sides 41 and 42. Depending sides 41 and 42 are joined togetherby a base section 43. The ends of depending side 41 carry retainer legs44 and 45 and the ends of depending side 41 carry retainer legs 46 and47. Depending sides 41 and 42 are parallel and are in friction slidingcontact with the adjacent channel walls 30 and 31. Base 43 carrieselongated guide head 48 which is sandwiched relatively tightly withinguide slot 34.

Slide block 40 is preferably fabricated of a solid plastic containing ahomogeneously dispersed solid lubricant. A preferred material for thisrequirement is nylon containing molybdenum disulfide. A plasticcomponent of nylon having controlled amounts of molybdenum disulfidehomogeneously dispersed therein is capable of producing a minimum wearin a component subjected to extensive cycling. Additionally, in view ofthe fact that in a door holder of the design described, slide block 40must be in close contact with the channel 23 in order to minimizeobjectionable looseness or play in the parts, the introduction of asolid lubricant in slide block 40, such as molybdenum disulfide,minimizes undesired friction which will detn'mentally effect theoperation of the device.

For further information concerning a preferred plastic containing asolid lubricant, reference is herein made to the article, MoldingResins," published by the Polymer Corporation of Reading, Pennsylvania,and also the article, Molybdenum Disulfide in Nylon for WearResistance," authored by Thomas E. Power and published in the June 1960issue of Modern Plastics.

Metal cam spring 50 is located between the depending legs 41 and 42 ofslide block 40.

In particular, rivets 51 and 52 fix the right end of cam spring 50 tobase 43 and head 48 of the slide block. The left end of cam spring 50 ismoved relative slide block 40 by means of friction adjustment screw 53housed within a stepped hole formed in base 43 and head 48 of the slideblock 40. Screw 53 is formed with a circular flange 54 which retains thescrew within the slide block. Screw nut 55 is received by the threadedportion of screw 53 so that selective rotation of the screw may drivethe nut upwardly or downwardly.

Cam spring 50 is formed with a generally V crimp 56 which serves as acam. The apex of cam 56 rests against metal plate 57 to which is bondedasbestos friction liner 58. Manual adjustment of friction screw 53 movesnut 55 so as to increase or decrease a downwardly directed force againstthe left end of cam spring 50 so that cam 56 may exert a greater orlesser pressure against friction subcombination 57, 58.

Accordingly, the degree of holding friction generated by the frictionassembly 16 and channel 28 may be manually adjusted by screw 53 toproduce a desired holding force which at the same time will,nonetheless, enable door 12 to be moved to a desired position with anon-objectionable manual force.

In view of the particular construction of slide block 40 which enablestight slidable engagement between the slide block and channel 23,channel 23 is coupled to the drive arm 22 without a looseness or playbetween components which characterized prior art door holders of thegeneral type described herein. This looseness, of course, is a problemwhich is generally inherent in a door holder of the type described,because drive arm 22 must not only pivot relative slide block 40 butalso must reciprocate the slide block within channel 23.

Drive arm 22 is coupled to slide block 40 by pivot pin 60 which passesthrough a hole 61 formed in drive arm 22, and a hole 62 formed in head48 and base 43 of slide block 40. Washer 63 is sandwiched between drivearm 22 and head 48 so as to facilitate relative rotation between drivearm 22 and slide block 40. Pivot 64 couples frame bracket 21 to the farend of drive arm 22. Bracket 21 is formed with a plurality of mountingholes 65 by which the bracket is fixed to a door frame or other supportstructure, as may be required.

FIG. 9 shows stop shock assembly 17. Shock assembly 17 serves thepurpose of absorbing an excessive door opening force which might producedoor racking. The shock assembly includes block 36 which carriescircular male tip 66. Helical shock absorber spring 67 is supported upontip 66 so that the spring is disposed in the path of slide block 40 whenthe door is opened to its extreme angular limit. The spring absorbs theexcess energy applied to the door and minimizes undesired destructiveforces.

FIG. shows the far end fragment of surface mounted channel 15. Inparticular, far end block 68 is formed with a horizontal hole 69. Whenblock 68 is inserted within channel 15, holes 25 and 69 are inalignment. The near end of channel containing the stop shock assembly(not shown) is correspondingly modified. These minor changes in surfacechannel 15 as compared to concealed channel 23 require no structuralchange in friction assembly 16. The only modifications required are inthe holes formed in the plastic end blocks, in that the mounting holesin channel 15 must be horizontal rather than vertical.

It should be understood that the structure herein described is merelyillustrative of the principles of this invention, and that modificationsmay be made without departing from the scope of the appended claims.

What is claimed is:

1. In a friction door holder having a door frame mounting bracket, adoor supported elongated, hollow channel formed with a pair of sidewalls, a bottom and a top having an elongated guide slot, with thechannel housing a friction assembly, and a friction assembly drive armcoupling the mounting bracket and friction assembly to move the frictionassembly relative the channel, the improved friction assembly comprisinga slide block slidably movable within the channel, the slide blockhaving an elongated body formed with generally parallel elongateddepending sides positioned closely adjacent the sides of the channel andjoined together by a base section located adjacent the slot, with thebody including an elongated guidehead projecting from the base andsandwiched between the edges of the guide slot, the drive arm beingpivotally coupled to a mid portion of the guide head, a support carryinga friction liner housed within the slide block, a cam element housedwithin the slide block with the cam element being adjustably supportedby the elongated guide head and the base section, an adjustment screwcarried by the guide head and the base section of the slide block tomove adjustably the cam to vary the degree of friction engagementbetween the friction liner and the channel bottom, and a plurality ofretainer legs projecting from the corner extremities of the slide blockdepending sides toward the channel bottom, the retainer legs serving asguide and limit stops for the support and friction liner.

2. The combination of claim I in which the friction liner projectsdownwardly beyond the retainer legs to establish friction contact withthe channel bottom with the retainer legs being the only portions of theslide block contacting'the friction liner.

3. The combination of claim 2 in which the cam is part of an elongatedspring fixed at one end to the base and guide head of the slide blockand the other end being free to move relative the slide block inresponse to manual variations in the screw adjustment.

4. The combination of claim 3 in which the cam is a generally V-shapedcrimp located substantially in the central portion of the elongatedspring to apply a single substantially centrally located force on thefriction liner.

5. In a friction door holder having a door frame mounting bracket, adoor supported elon ated, hollow channel ormed with a pair 0 side walls,a ottom and a top having an elongated guide slot, with the channelhousing a friction assembly, and a friction assembly drive arm couplingthe mounting bracket and friction assembly to move the friction assemblyrelative the channel, the improved friction assembly comprising a slideblock slidably movable within the channel, the slide block having agenerally U-shaped elongated body formed with generally parallelelongated depending sides positioned closely adjacent the sides of thechannel and joined together by a base section located adjace nt theslot, with the body including firstly an elongated guide head projectingfrom the base and sandwiched between the edges of the guide slot andsecondly a plurality of projecting retainer legs projecting from thecorner extremities of the depending sides toward the channel bottom, ametal plate carrying a friction liner housed within the slide blockbetween the slide block legs to be retained and guided thereby, anelongated cam spring housed within the slide block with one end fixed tothe slide block and the other end being free to move relative the slideblock, and an adjustment screw carried by the slide block to contactadjustably the free end of the cam spring to vary the degree of frictionengagement between the friction liner and the channel.

6. The combination of claim 5 in which the slide block is fabricated ofa solid plastic containing a homogeneously dispersed solid lubricant.

7. The combination of claim 6 in which the plastic is nylon and thesolid lubricant is molybdenum disulfide.

2. The combination of claim 1 in which the friction liner projectsdownwardly beyond the retainer legs to establish friction contact withthe channel bottom with the retainer legs being the only portions of theslide block contacting the friction liner.
 3. The combination of claim 2in which the cam is part of an elongated spring fixed at one end to thebase and guide head of the slide block and the other end being free tomove relative the slide block in response to manual variations in thescrew adjustment.
 4. The combination of claim 3 in which the cam is agenerally V-shaped crimp located substantially in the central portion ofthe elongated spring to apply a single substantially centrally locatedforce on the friction liner.
 5. In a friction door holder having a doorframe mounting bracket, a door supported elongated, hollow channelformed with a pair of side walls, a bottom and a top having an elongatedguide slot, with the channel housing a friction assembly, and a frictionassembly drive arm coupling the mounting bracket and friction assemblyto move the friction assembly relative the channel, the improvedfriction assembly comprising a slide block slidably movable within thechannel, the slide block having a generally U-shaped elongated bodyformed with generally parallel elongated depending sides positionedclosely adjacent the sides of the channel and joined together by a basesection located adjacent the slot, with the body including firstly anelongated guide head projecting from the base and sandwiched between theedges of the guide slot and secondly a plurality of projecting retainerlegs projecting from the corner extremities of the depending sidestoward the channel bottom, a metal plate carrying a friction linerhoused within the slide block between the slide block legs to beretained and guided thereby, an elongated cam spring housed within theslide block with one end fixed to the slide block and the other endbeing free to move relative the slide block, and an adjustment screwcarried by the slide block to contact adjustably the free end of the camspring to vary the degree of friction engagement between the frictionliner and the channel.
 6. The combination of claim 5 in which the slideblock is fabricated of a solid plastic containing a homogeneouslydispersed solid lubricant.
 7. The combination of claim 6 in which theplastic is nylon and the solid lubricant is molybdenum disulfide.